Origin Validation Error Affecting github.com/mattermost/mattermost/server/channels/api4 package, versions <10.11.11>=11.2.0-rc1 <11.2.3>=11.3.0-rc1 <11.3.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMMATTERMOSTMATTERMOSTSERVERCHANNELSAPI4-15702038
- published20 Mar 2026
- disclosed16 Mar 2026
- creditdaw10
Introduced: 16 Mar 2026
NewCVE-2026-2457 Â (opens in a new tab)How to fix?
Upgrade github.com/mattermost/mattermost/server/channels/api4 to version 10.11.11, 11.2.3, 11.3.1 or higher.
Overview
Affected versions of this package are vulnerable to Origin Validation Error via the post update API endpoint when client-supplied post metadata is not properly sanitized. An attacker can impersonate other users and spoof permalink embeds by sending crafted PUT requests.